Actionable comments posted: 2

crates/vm/src/stdlib/codecs.rs (2)

239-316: Consider overflow check for large strings (optional).

The implementation correctly handles MBCS encoding with proper surrogate checking, two-pass buffer sizing, and strict error handling. However, the casts from wide.len() to i32 (lines 270, 291) could theoretically overflow for extremely large strings (> 2GB).

This is unlikely in practice and aligns with similar limitations in CPython's implementation.

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436-513: Consider overflow check (optional); note code duplication.

The oem_encode implementation is nearly identical to mbcs_encode (differing only in using CP_OEMCP instead of CP_ACP). The same optional consideration applies regarding potential i32 overflow for extremely large strings.

Optional refactor: Consider extracting a common helper function to reduce duplication between mbcs_encode and oem_encode.

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Reviewing files that changed from the base of the PR and between 8781de6 and 0e0bd1e.

• Lib/test/test_faulthandler.py is excluded by !Lib/**
• Lib/test/test_shutil.py is excluded by !Lib/**
• Lib/test/test_subprocess.py is excluded by !Lib/**

• crates/vm/src/stdlib/codecs.rs (1 hunks)
• crates/vm/src/stdlib/msvcrt.rs (1 hunks)
• crates/vm/src/stdlib/stat.rs (1 hunks)
• crates/vm/src/stdlib/winapi.rs (4 hunks)
• crates/vm/src/windows.rs (1 hunks)

• crates/vm/src/stdlib/msvcrt.rs
• crates/vm/src/stdlib/stat.rs

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**/*.rs: Follow the default rustfmt code style by running cargo fmt to format Rust code
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Files:

• crates/vm/src/stdlib/winapi.rs
• crates/vm/src/stdlib/codecs.rs
• crates/vm/src/windows.rs

Learnt from: moreal
Repo: RustPython/RustPython PR: 5847
File: vm/src/stdlib/stat.rs:547-567
Timestamp: 2025-06-27T14:47:28.810Z
Learning: In RustPython's stat module implementation, platform-specific constants like SF_SUPPORTED and SF_SYNTHETIC should be conditionally declared only for the platforms where they're available (e.g., macOS), following CPython's approach of optional declaration rather than providing fallback values for other platforms.

Learnt from: moreal
Repo: RustPython/RustPython PR: 5847
File: vm/src/stdlib/stat.rs:547-567
Timestamp: 2025-06-27T14:47:28.810Z
Learning: In RustPython's stat module implementation, platform-specific constants like SF_SUPPORTED and SF_SYNTHETIC should be conditionally declared only for the platforms where they're available (e.g., macOS), following CPython's approach of optional declaration using #ifdef checks rather than providing fallback values for other platforms.

crates/vm/src/stdlib/os.rs (1)

• errno_err (39-41)

crates/vm/src/stdlib/nt.rs (1)

• from_utf16 (327-329)

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crates/vm/src/windows.rs (1)

172-172: LGTM! Correct symlink file type handling.

The change properly clears existing file type bits using S_IFMT mask before setting the Windows-specific symlink type. This prevents invalid combined file type bits that could result from OR-ing with the previous mode.

crates/vm/src/stdlib/winapi.rs (3)

88-102: LGTM! Proper handle error and null handling.

The refactored GetStdHandle correctly distinguishes between:

• INVALID_HANDLE_VALUE → returns error via errno_err(vm)
• NULL handle → returns None (e.g., detached console)
• Valid handle → returns Some(HANDLE)

This pattern aligns with Rust idioms and provides proper error propagation to Python.

---

127-128: LGTM! Improved API ergonomics.

Splitting the source handle into two separate parameters (src_process and src) instead of a tuple makes the API more intuitive and idiomatic.

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308-311: LGTM! ExitProcess added for process termination.

The function exposes Windows' ExitProcess API, which terminates the process immediately without running destructors or cleanup handlers. This is analogous to Python's os._exit() and is appropriate for the low-level _winapi module.